BIG BANG

About 14 billion years ago nothing existed in the universe until the big bang. The Big Bang theory is an effort to explain what happened at the very beginning of our universe. Prior to that moment there was nothing; during and after that moment there was nothing in our universe. According to the standard theory, our universe sprang into existence as "singularity" around 13.7 billion years ago. The big bang theory is an effort to explain what happened during and after that moment. The big bang is the origin of space and time. Forests ocean people everything in the universe is made from matter created in first seconds of the big bang. The big bang is the defining event of our universe and everything in it. The origin of the big bang is the greatest mystery of all time. 
Until 1929 we thought that our universe is static when astronomer Edwin Hubble discovered that galaxies are not static in one place, not only they are moving but they are flying away from us at incredible speeds and this was the first evidence of big bang. Hubble noted that galaxies outside our own Milky Way were all moving away from us, each at a speed proportional to its distance from us. The conclusion was made that the universe is expanding so for an expanding universe they must have started from a single point. So by measuring how fast the universe is expanding the astronomers calculated backwards and worked out when it bursts into life it was like reverse engineering. Astronomers combine mathematical models with observations to develop workable theories of how the Universe came to be. The mathematical underpinnings of the Big Bang theory include Albert Einstein's general theory of relativity along with standard theories of fundamental particles. Today NASA spacecraft such as the Hubble Space Telescope and the Spitzer Space Telescope continue Edwin Hubble's work of measuring the expansion of the Universe. One of the goals has long been to decide whether the Universe will expand forever, or whether it will someday stop, turn around, and collapse in a "Big Crunch?"  Everything before the big bang was compressed in a very small region with incredibly hotness it was not matter that time but just the point of energy. In the big bang the pure energy created into the matter according to the Einstein mass energy relation E=mc2. The earliest matter was too unstable to form the matter which we know today.
There are many misconceptions surrounding the Big Bang theory. For example, we tend to imagine a giant explosion. Experts however say that there was no explosion but there was an expansion. Rather than imagining a balloon popping and releasing its contents, imagine a balloon expanding: an infinitesimally small balloon expanding to the size of our current universe. Another misconception is that we tend to image the singularity as a little fireball appearing somewhere in space. According to the many experts however, space didn't exist prior to the Big Bang. Back in the late '60s and early '70s, when men first walked upon the moon, "three British astrophysicists, Steven Hawking, George Ellis, and Roger Penrose turned their attention to the Theory of Relativity and its implications regarding our notions of time. In 1968 and 1970, they published papers in which they extended Einstein's Theory of General Relativity to include measurements of time and space. According to their calculations, time and space had a finite beginning that corresponded to the origin of matter and energy. The singularity didn't appear in space; rather, space began inside of the singularity. Prior to the singularity, nothing existed, not space, time, matter, or energy - nothing. So where and in what did the singularity appear if not in space? We don't know. We don't know where it came from, why it's here, or even where it is. All we really know is that we are inside of it and at one time it didn't exist and neither did we.
The whole process started from pure energy. Pure energy also produces one of the dangerous thing in the universe “antimatter”. It is the mirror image of the ordinary matter. Matter and antimatter are differently charged. If there would be equal amount of matter and the antimatter then they would have canceled each other but there were more matter than the antimatter which is responsible for the universe.   Then the temperature starts dropping and the primitive particles started slowing down. Now they started bonding together to form the first atoms. The first one that was formed was hydrogen. Then over the three minutes the universe begins to create two more elements helium and lithium. In 14 billion years since the big bang galaxies have been created filled with stars planets and moons and the universe being expanding the whole time.